A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 3412020 can be evenly divided by 1 2 3 4 5 6 10 12 15 19 20 30 38 41 57 60 73 76 82 95 114 123 146 164 190 205 219 228 246 285 292 365 380 410 438 492 570 615 730 779 820 876 1,095 1,140 1,230 1,387 1,460 1,558 2,190 2,337 2,460 2,774 2,993 3,116 3,895 4,161 4,380 4,674 5,548 5,986 6,935 7,790 8,322 8,979 9,348 11,685 11,972 13,870 14,965 15,580 16,644 17,958 20,805 23,370 27,740 29,930 35,916 41,610 44,895 46,740 56,867 59,860 83,220 89,790 113,734 170,601 179,580 227,468 284,335 341,202 568,670 682,404 853,005 1,137,340 1,706,010 and 3,412,020, with no remainder.
Since 3,412,020 cannot be divided by just 1 and 3,412,020, it is not a prime number.